1. Field
The following description relates to a technology of locating, and more particularly, to a method and apparatus for locating a mobile terminal by use of a message received from the mobile terminal.
2. Description of the Related Art
The current location of a user possessing a mobile terminal may be recognized using various techniques.
In a first example, the current location of a user may be recognized through a Global Positioning System (GPS) receiver that is installed on the mobile terminal and which receives location information from a GPS satellite. In this example, however, the mobile terminal further needs to have the GPS receiver, creating an additional cost for installation, leading to implementation complexity, and exhibiting a position error to some degree. In addition, the accuracy of positioning is susceptible to weather, environmental factors (e.g., trees and buildings), and topology. Assisted GPS uses an operator-maintained ground station to correct for GPS errors caused by the atmosphere and/or topography. Assisted GPS positioning typically uses cell-based positioning methods when indoors or when buildings or trees block the GPS reception.
In a second example, the current location of a user may be recognized by use of location information of a base station to which the mobile terminal is connected. This is based on measuring power levels and antenna patterns and assumes that a mobile phone always communicates wirelessly with one of the closest base stations, so if it is known which base station the phone communicates with, it can be determined that the phone is close to that base station. The base station is a stationary entity, and the mobile terminal resides within the coverage of the base station. Accordingly, if a query is performed as to which base station the mobile terminal is connected, the schematic location of the mobile terminal can be estimated. This example does not use an additional apparatus for locating the mobile terminal, but exhibits great position error.
In a third example, the current location of a user may be recognized by use of location information of an access router to which the mobile terminal is connected through a wireless LAN interface. This example needs a wireless LAN access apparatus to be installed, and is available for use only when an access router exists nearby, and creates additional communication cost.